The purpose of the present study was to evaluate the use of leaves from
the Jack fruit tree (Artocarpus heterophyllus), banana plants (Musa spp), Acacia
mangium and Trichantera gigantea trees as supplements to a basal diet of rice
straw and sugarcane tops, feed resources which are widely available in North Vietnam
especially in the winter season. The leaves were fed to lactating goats which were
allocated to the treatments from the 4th to the 12th week of lactation. From kidding until
the end of the 4th week the goats were fed a standard diet of Guinea grass (Panicum
maximum) supplemented with 500 g/head/day of a 15% protein concentrate. During the
first two weeks the kids were always with the mother. At the start of the 3rd week the
kids were separated and the does were milked once daily (07.00hr); the kids were allowed
to suck for 30 minutes after milking in the morning and again in the afternoon (16.00hr)
without prior milking of the dam. During the 4th week the yield was measured by weighing
the milk produced at milking and by estimating the milk consumed by the kids by weighing
them before and after suckling. The yield in the 4th week was used as covariate to adjust
the yield during the experiment.

The highest milk yields were obtained from goats fed leaves from Jack
fruit (765 ml/day) and Acacia mangium (736 ml/day) which did not differ
significantly from each other. Both were superior to bananas (676 ml/day) while the Trichantera
gigantea was the worst (571 ml/day). The does gained weight on the Jack fruit
treatment (1.85 kg from 7 to 12 weeks) but lost weight (-1.24 to -2.2 kg) on the other
treatments. The growth rates of the kids were lowest on Acacia mangium (14g/day)
and ranged from 48 to 60 g/day on the other treatments.

It is concluded that a diet of sugar cane tops, molasses-urea block and
leaves from the Jack fruit tree, with small amounts of rice bran (200 g/day) can be
recommended as a basal diet for lactating goats and growing kids, especially during the
dry winter season when grasses are in short supply.

The conventional feeding system for dairy goats in Vietnam is based on
the use of grasses, natural and improved, supplemented with concentrates. In the North of
Vietnam the dry winter season is difficult for forage production, as the natural pastures
become dry and the improved grasses cannot grow. It is also important to find an
alternative for the concentrates as these are becoming increasingly scarce and expensive
because of competition from poultry and pigs. In view of this situation, research at this
Centre is directed towards the development of alternative feeding systems which make use
of local resources that are available the year round.

In contrast with grasses, sugar cane gives highest biomass yield and
best quality (percent sugars in the juice) when harvested during the dry winter season.
The multi-purpose tree Acacia mangium also grows better than other trees such as Leucaena
leucocephala at this time. The leaves of Acacia mangium are of low
degradability in the rumen of cattle (Bui Xuan An et al 1992). Despite this apparent
limitation, it was found in an earlier study at this Centre (Dinh van Binh and Preston
1995) that sugarcane tops supplemented with a molasses-urea block, rice bran and foliage
from Acacia mangium could replace the conventional diet of Guinea grass and
concentrates with improvements in milk yield and growth of the kids.

Other sources of leaves which are available in the winter season are
the Jack fruit tree (Artocarpus heterophyllus), banana plants (Musa spp) and
Trichantera gigantea, a multi-purpose tree recently introduced from the
coffee-growing areas of Colombia.

The purpose of the present study was to evaluate the use of leaves from
the above trees as supplements to a basal diet of rice straw and sugarcane tops, feed
resources which are widely available in Vietnam especially in the winter season.

Material and methods

Treatments and design

The four treatments were the leaves of:

Acacia mangium (AM)

Bananas (BAN)

Jack fruit (JF)

Trichantera gigantea (TG)

Table 1: Content of
dry matter in fresh samples and of protein(N*6.25) in the dry matter

Dry matter

N*6.25

A mangium

31.7

17

Banana

22.5

13.8

Jack fruit

26.9

18.1

T gigantea

19.0

12.5

SC tops

21

4.5

MUB

74.5

31.6

Rice bran

87.6

13

Guinea grass

19.9

13

Concentrate

90.3

15

Rice straw

39

22.1

They were fed to lactating goats (n=20) of the Bach Thao, Barbari,
Jamnapari and Beetal breeds (the last three recently imported from India).The goats were
allocated to the treatments when they reached the end of the 4th week of lactation and
continued on the experimental diets until the end of the 12th week of lactation.

Management and feeding

From kidding until the end of the 4th week the goats were fed the
control diet of Guinea grass (Panicum maximum) supplemented with 500 g/head/day of
a 15% protein concentrate. During the first two weeks the kids were always with the
mother. At the start of the 3rd week the kids were separated and the does were milked once
daily (07.00hr); the kids were allowed to suck for 30 minutes after milking in the morning
and again in the afternoon (16.00hr) without prior milking of the dam. During the 4th week
the yield was measured by weighing the milk produced at milking and by estimating the milk
consumed by the kids by weighing them before and after suckling. The yield in the 4th week
was used as covariate to adjust the yield during the experiment.

From the beginning of the 5th week the experimental diet was introduced
gradually replacing the standard diet over a period of 3 days.

The 5th and 6th week were considered as the "changeover"
period and from 7 to12 weeks as "experimental" for evaluation of the diets.

The liveweight of the does was recorded at the beginning of the
experiment (day 43 from parturition) and at intervals of 10 days subsequently. Kids were
weighed every 7 days. Feed offered and refused was measured daily. Samples of offered
feeds were analysed for dry matter and nitrogen. Milk consumed by the kids was determined
by weighing them before and after suckling.

Results and discussion

Milk production

Average milk yields during the "standard" period (week 4 used
as covariate) and the experimental weeks 7 though 12 are presented in Figure 1 and in
Table 2 together with the mean yield for weeks 7 through 12. The experimental data are
"adjusted" yields after correction by covariance for yield in the standard
period. Best results were with leaves from the Jack fruit tree and from Acacia mangium
which did not differ significantly from each other. Both were superior to bananas while
the Trichantera gigantea was the worst.

Table
2: Mean values for "adjusted*" total daily milk yield from week 7 to week 12
of lactation of goats fed leaves from Jackfruit, A mangium, bananas and Trichanthera
gigantea as supplements to sugar cane tops and rice straw

Week

JF

AM

BAN

TG

SE/Prob

------------g/head/day-------

4*

1275

1134

1170

1230

±26/0.001

7

848

806

760

613

±47/0.003

8

764

731

674

575

±36/0.002

9

779

748

618

555

±32/0.001

10

748

736

625

600

±27/0.001

11

857

778

754

571

±23/0.001

12

596

617

627

512

±21/0.001

Mean
(7-12)

765

736

676

571

±25/0.001

* Used as covariate to adjust milk yields in weeks 7 through 12

The changes in weight of the does and the kids from week 7 to week 10
when they received the experimental diets are shown in Table 3. The weight changes of the
does were mostly in line with results for milk yield, with the does fed Jack fruit leaves
gaining 1.85 kg while those on the other treatments all lost weight the differences
between the Jack fruit and the rest being significant (P=0.01). All the kids gained in
weight with those on the Jack fruit, Acacia mangium and Trichantera gigantea showing
normal growth (48-60 g/day) while those fed banana leaves had significantly lower growth
rates (14 g/day).

The good results with Jack fruit leaves as the supplement are confirmed
by the study of Keir et al (19Jack), also carried out at our Centre. The average growth
rate of kids fed only foliage from Jack fruit plus molasses-urea blocks was 67 g/day,
while kids fed foliage from Trichantera gigantea lost weight. Preliminary
observations at the University of Agriculture and Forestry, in South Vietnam, of lactating
goats fed only leaves from Jack fruit trees were that they had high voluntary intakes and
that milk yield was sustained at pre-experimental levels (Rodriguez Lylian, 1996, personal
communication)

Feed intakes

Mean values for the intake of dietary constituents are shown inTable 4.
Highest intakes of fresh leaves was for the Jack fruit treatment (1,640g/d), followed by
bananas (1,100), then Trichantera gigantea 998) with lowest intake on the Acacia
mangium (710). The goats ate very little of the urea-treated rice straw with highest
intake (78g/d) on the TG treatment and lowest (25g/d) on BAN. Intake of sugar cane tops
was similar on all treatments (1,100 to 1,450g/d). Most MUB was consumed by goats on the
JF treatment (213g/d) and least on TG (120g/d). Intake of rice bran varied very little
(217 to 237g/d).

Conclusions

Leaves of the Jack fruit tree appear to be of superior nutritive value to all other
leaves tested as a supplement to a low-protein, carbohydrate-rich diet as provided by
sugar cane tops, rice straw and molasses-urea block. The leaves from Trichantera
gigantea supported the poorest performance.

A diet of sugar cane tops, molasses-urea block and leaves from the Jack fruit tree can
be recommended as a basal diet for lactating goats and growing kids, especially during the
dry winter season when grasses are in short supply.

Acknowledgements

This study was partially financed by the International Foundation or
Science through a grant to Nguyen Thi Duyen (B/2357-1).

References

Bui Xuan An, Luu Trong Hieu, Duong Khang Nguyen and Preston T R1992

Effect of position in the tree and pretreatment of Acacia mangium leaves on rumen
dry matter and nitrogen degradabilities. Livestock Research for Rural Development, Volume
4, Number 2:7-12